Code formatting updates (#4502)

* Editorconfig: Add space_before_self_closing setting

This was a difference between the way dotnet-format and Rider format code. See https://www.jetbrains.com/help/rider/EditorConfig_Index.html

* Editorconfig: Keep 4 spaces indentation for Swagger JSON files

They are all formatted that way, let's keep it like that.

* Apply dotnet-format, mostly white-space related changes

BTCPayServer.Data/Data/StoreSettingData.cs

@@ -11,7 +11,7 @@ public class StoreSettingData
     public string Value { get; set; }
 
     public StoreData Store { get; set; }
-        
+
     public static void OnModelCreating(ModelBuilder builder, DatabaseFacade databaseFacade)
     {
         builder.Entity<StoreSettingData>().HasKey(data => new { data.StoreId, data.Name });